Saturday 12 May 2012 16.30 EDT
First published on Saturday 12 May 2012 16.30 EDT

Frank Warren has warned the British Boxing Board of Control he will take legal action if they do not withdraw a threat to revoke his licence for promoting the fight between Dereck Chisora and David Haye at Upton Park on 14 July. The board objects to two unlicensed fighters taking part in a bout they have not sanctioned and which will be supervised by a foreign organisation within the board's jurisdiction.

The row between the promoter and the board threatens to cause the most serious rift in British boxing since the war. "My concern," Warren said in a letter to the board, "is that by issuing the threat contained in your press release [to suspend license-holders who take part in the promotion] you are trying to stop me from being involved in a legitimate and lawful fight governed by another federation and to interfere with my freedom to earn a living.

"I am worried that you have taken this decision not because you are really concerned about the fight … but because you are fearful that you will lose your monopoly in the UK."

Warren said he had not, as claimed, breached the board's rules because, "the Fédération Luxembourgeoise de Boxe [which is sanctioning the fight] is affiliated to and recognised by the board; both are affiliated to the EBU."

Warren demanded the board inform him before Wednesday that, "you will not seek to take away my licence if I remain Dereck Chisora's manager".

He said: "If I do not receive your confirmation then you will receive a formal complaint from my solicitors followed by proceedings (including injunctive relief should they consider it necessary and appropriate). There may well be issues of costs and damages associated with your actions and I put you on notice that I will be seeking these also if so advised."